Already invested time creating some html code for email signature on thunderbird. Wanted to create something prepared for dark modes on IOS. Everything was fine until I detected on IOS (dark mode)some white rectangles outside my email signature code. It´s a problem that I cannot solve because it´s outside my code, and I´m wondering if you are already aware of this issue. In case you want to test my code on a Thunderbird HTML email signature and see the result on an iPhone (dar mode), you can get it here: https://codeshare.io/dekBnR